Haloacetic acids (HAA9)

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of nine haloacetic acids includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid, which are regulated as a group by the federal government (HAA5); and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid, and tribromoacetic acid. Read More.

Haloacetic acids are harmful during pregnancy and may increase the risk of cancer. Haloacetic acids are genotoxic, which means that they induce mutations and DNA damage. Multiple studies by the National Toxicology Program have demonstrated the cancer-causing properties of individual haloacetic acids in laboratory animals. The Department of Health and Human Services is currently considering listing di- or tri-haloacetic acids for possible inclusion in its comprehensive Report on Carcinogens